Method for disassembling heavy-water reactor equipment by using cutting device

Abstract

A method for decommissioning a heavy water reactor facility includes: opening an upper part of the calandria vault; inserting a support device into an inner part of the calandria vault through the upper part of the calandria vault to support the main shell of the calandria; cutting between the main shell and the sub-shell of the calandria by inserting a cutting device into the inner part of the calandria vault through the upper part of the calandria vault; and drawing out the main shell of the calandria to the outside of the calandria vault by moving the support device from the inner part of the calandria vault to the outside through the upper part.

The invention claimed is: 
     
       1. A method for decommissioning a heavy water reactor facility that includes a calandria including a main shell and a sub-shell connected to the main shell, and a calandria vault supporting the sub-shell of the calandria to accommodate the calandria therein, comprising:
 opening an upper part of the calandria vault; 
 inserting a support device into an inner part of the calandria vault through the upper part of the calandria vault to support the main shell of the calandria; 
 cutting between the main shell and the sub-shell of the calandria by inserting a cutting device into the inner part of the calandria vault through the upper part of the calandria vault; and 
 drawing out the main shell of the calandria to the outside of the calandria vault by moving the support device from the inner part of the calandria vault to the outside through the upper part, 
 wherein 
 the support device includes: 
 two first vertical moving rails spaced apart from each other with the calandria interposed therebetween; and 
 a first opening/closing type of fixing ring that is supported by the first vertical moving rails to move up and down, and 
 the first opening/closing type of fixing ring selectively forms a U-shape or O-shape. 
 
     
     
       2. The method for decommissioning the heavy water reactor facility of  claim 1 , wherein
 the heavy water reactor facility further includes a reactivity mechanism deck that is supported on the upper part of the calandria vault and covers the calandria, and 
 the opening of the upper part of the calandria vault includes separating the reactivity mechanism deck from the calandria vault. 
 
     
     
       3. The method for decommissioning the heavy water reactor facility of  claim 2 , wherein
 the opening of the upper part of the calandria vault further includes expanding the upper part of the calandria vault. 
 
     
     
       4. The method for decommissioning the heavy water reactor facility of  claim 1 , wherein
 the supporting of the main shell of the calandria includes: 
 inserting the first opening/closing type of fixing ring into the inner part of the calandria vault in the U-shape having an opened lower side along the first vertical moving rails; and 
 surrounding and supporting the main shell of the calandria with the first opening/closing type of fixing ring of the O-shape. 
 
     
     
       5. The method for decommissioning the heavy water reactor facility of  claim 1 , wherein
 the cutting device includes: 
 two second vertical moving rails spaced apart from each other with the calandria interposed therebetween; 
 a second opening/closing type of fixing ring that is supported by the second vertical moving rails to move up and down; and 
 a cutting part supported on the second opening/closing type of fixing ring to move along the second opening/closing type of fixing ring, and 
 the second opening/closing type of fixing ring selectively forms a U-shape or O-shape. 
 
     
     
       6. The method for decommissioning the heavy water reactor facility of  claim 5 , wherein
 the cutting between the main shell and the sub-shell of the calandria includes: 
 inserting the second opening/closing type of fixing ring into the inner part of the calandria vault in the U-shape having an opened lower side along the second vertical moving rails; 
 surrounding between the main shell and the sub-shell of the calandria with the second opening/closing type of fixing ring of the O-shape; and 
 moving the cutting part along the second opening/closing type of fixing ring to cut between the main shell and the sub-shell of the calandria.